The subject matter of the present invention is related to U.S. Pat. No. 3,849,032 which is similarly directed to a high pressure reciprocating pump and which is owned by the assignee of the present invention. The present invention pertains to various improvements directed to components of the high pressure pump described therein and as will be more fully described hereinafter.
High pressure pumps of the type disclosed herein are particularly useful for application such as car wash operations, or any other similar operation where it is desired to discharge a fluid such as water at a relatively high pressure. It will be appreciated that most such operations involve a cleaning process where the pressure of the fluid discharged from the pump is intended to perform a cleaning function by relying upon the pressure of the fluid ejected from the pump. It will therefore be appreciated that it is desirable to provide a high pressure pump which incorporates components having the ability to withstand high fluid pressures in order to function efficienty. It has been found to be further desirable to provide a high pressure pump wherein the various components will have a long useful life in order to minimize the down time of the machinery with the attendant cost of repairs.
As will be noted from a review of Pat. No. 3,849,032, the high pressure pump described therein provided an improved valve assembly in that the valve construction was formed by a valve housing having a valve cap positioned therein and seating against a valve seat formed as a separate element, that is, separate from the valve housing. The construction of the valve assembly was essentially completed by providing an annular elastomeric seal and an anchoring ring, as separate elements, the elastomeric seal overlying and maintaining the valve housing and valve seat in position. The valve seat, in turn, in use, is placed in a approproiate entry or discharge port, the annular elastomeric seal functioning to frictionally position the valve assembly in position. It will therefore be appreciated that the valve assembly as described in U.S. Pat. No. 3,849,032 is intended as a basic three part construction, the three parts basically including the valve housing, the valve seat, and the annular elastomeric seal.
It was found however, that upon prolonged use of the high pressure pump, the elastomeric seal would peel back or extrude and cause a floating of the valve assembly within the corresponding port. This would, in turn, cause leaking through the valve assembly and necessitate that the pump be torn apart for the purpose of replacing the valve assembly in order provide a tighter elastomeric seal to firmly position the valve assembly within the appropriate port. Hence, while the valve assembly as described therein achieved an improved construction at the time, it has now been found to be desirable to further improve the valve assembly in order to achieve a much improved and longer lasting pump assembly.
It was further found that additional improvements could be effected over the pump shown in U.S. Pat. No. 3,849,032 in order to further improve the life of the pump as well as the efficiency thereof. In this connection, it was found that the plunger generally associated with high pressure pumps such as the type described above generally provide a solid cylindrical plunger which reciprocates within the cylindrical chamber. A packing system is provided in such pumps which include a grease ring associated with a grease fitting so that grease may be applied to the packing with the attendant result that the plunger would be lubricated during the reciprocating movement thereof. While this was found to be reasonably efficient, nevertheless, in view of some of the usages of such pumps, the plunger has a tendency to wear due to the abrasive materials which are carried by the fluid being pushed through the pump. For example, where such pumps are used in a car wash assembly, the fluid employed is water, and usually, detergent materials are used with the water. During periods of prolonged non-use, the detergent has a tendency to settle out of the fluid and return to granular form. Hence, any fluid existing in the cylindrical cylinder containing the plunger will contain a fair quantity of particlized detergent. When the pump is then reactivated, as the plunger reciprocates through the packing system, the abrasive materials have a tendency to score and deteriorate the outer surface of the plunger. This, in turn, will ultimately cause fluid to leak through the packing system and may ultimately find its way into the crank case. Leaks of this type require that the pump be dismantled with a view toward changing the plunger in order to provide a plunger having a smooth and integral surface to eliminate such types of leaks.
It was further noted that in order to change the ratio of incoming fluid to discharge fluid, an entirely different pump was necessary. For example, a pump designed to discharge six gallons of fluid per minute, would have a particular plunger diameter and in order to vary that discharge rate, a pump having a different plunger diameter must be substituted therefor. Hence, it has been found that by changing the plunger arrangement, and specifically, by providing a two-piece plunger as opposed to a one-piece plunger, not only can the wet end of the plunger be easily replaced in the event of an abraded surface, but also, one can vary the diameter of the wet end portion of the plunger without at the same time requiring that the pump be replaced, or that the entire plunger be removed in order to fit either a larger or a smaller diameter plunger. Hence, it has been found that additional improvements can be made with regard to the plunger assembly culminating in an overall more efficient pump assembly.
Another area where some difficulties have been found relate to the crank case housing and the manner in which the same is drained. The prior art devices as exemplified by U.S. Pat. No. 3,849,032 generally provide a crank case housing wherein the internal portion of the housing sits relatively parallel to an underlying support surface such that the bottom wall is reasonably flat. Drain holes are positioned in either the side walls or the back wall of the housing and fitted with a drain plug which may be removed in order to remove the sludge and oil from the crank case in order to replace the same with fresh oil. While theoretically this arrangement should operate efficiently, nevertheless it has been found that crank case oil often contains a great deal of heavy sludge which is more solid than liquid, and hence, upon draining the fluid from the crank case, a good portion of the sludge will not normally drain from the crank case housing by natural gravity flow. Hence, as the lubricating oil is replenished constantly, a greater degree of sludge is left behind in the crank case, until utilimately, the build-up of sludge causes problems with the crank shaft. The present invention provides an improved construction of the crank case housing, which in combination with the other features to be described more fully hereinafter, provides a high pressure pump which has a manifestly longer useful life than heretofore possible in the past.
In connection with the provision of a packing system, it has also been the practice to provide a packing system which includes a base V-ring which is interposed between the plurality of annular packing rings, and the coil spring which butts against the forward wall of the cylindrical chamber. Generally, such base V-rings are formed of an elastomeric material, and it has been found that various problems arise because of this construction. For example, generally the coil spring which is provided has a final turn in the spring which is bottomed against the base V-ring, and an opposed final turn which butts against the cylinder chamber wall. The final turn which butts against the base V-ring has been found to cause cocking and fracturing of the base V-ring due to the fact the same is formed of an elastomeric material. It has been found that once the base V-ring commences to cock, after prolonged usage, the points of cocking will utlimately fracture and this causes fluid to leak through the packing system and hence leak into the crank case housing. Once again, one feature of the present invention is to improve upon the packing system, which in combination with the other features described herein again prolong the useful life of the pump many times that normally experienced in the past.
Finally, it has been found to be beneficial to provide improved seals for not only the valve assemblies, but also the sealing system for the plunger arrangement within the cylindrical chamber in order to positively insure that lubricating fluid from the crank case housing will not leak into the wet part of the pump, and alternatively, that fluid from the wet part of the pump will not leak into the crank case housing. In the past, it has been found that the sealing arrangement employed around the plunger has been less than efficient, such that fluids will tend to leak and intermix in the crank case housing as well as in the wet end of the pump. The present invention again seeks to improve upon the sealing system employed, especially in the area around the plunger in order to positively eliminate the problem of the exchange of fluids therebetween.